reshape(-1,1)

Question

前提・実現したいこと

reshape(-1,1)を使いたいのですがどのように使ったらいいのかわかりません!
教えてください、お願いします!

発生している問題・エラーメッセージ

エラーメッセージ

ValueError                                Traceback (most recent call last)
<ipython-input-26-9f692dcedeec> in <module>()
      1 np.reshape(-1,1)
----> 2 num_rooms_std=sc_x.transform([5.0])
      3 price_std=lr.predict(num_rooms_std)
      4 print("Price in $1000s: %.3f" % sc_y.inverse_transform(price_std))

~/.pyenv/versions/anaconda3-5.3.1/lib/python3.7/site-packages/sklearn/preprocessing/data.py in transform(self, X, y, copy)
    679         copy = copy if copy is not None else self.copy
    680         X = check_array(X, accept_sparse='csr', copy=copy, warn_on_dtype=True,
--> 681                         estimator=self, dtype=FLOAT_DTYPES)
    682 
    683         if sparse.issparse(X):

~/.pyenv/versions/anaconda3-5.3.1/lib/python3.7/site-packages/sklearn/utils/validation.py in check_array(array, accept_sparse, dtype, order, copy, force_all_finite, ensure_2d, allow_nd, ensure_min_samples, ensure_min_features, warn_on_dtype, estimator)
    439                     "Reshape your data either using array.reshape(-1, 1) if "
    440                     "your data has a single feature or array.reshape(1, -1) "
--> 441                     "if it contains a single sample.".format(array))
    442             array = np.atleast_2d(array)
    443             # To ensure that array flags are maintained

ValueError: Expected 2D array, got 1D array instead:
array=[5.].
Reshape your data either using array.reshape(-1, 1) if your data has a single feature or array.reshape(1, -1) if it contains a single sample.

該当のソースコード

num_rooms_std=sc_x.transform([5.0])
price_std=lr.predict(num_rooms_std)
print("Price in $1000s: %.3f" % sc_y.inverse_transform(price_std))

Comments

[meg_]

「reshape(-1,1)を使いたい」のは何故ですか？　実行可能（検証可能）なコードを提示してください。